On the Active Topics page, (the one most people probably go to), it says "Display posts from previous: 7 days" at the bottom of the page.

I suggest that this feature be disabled as it makes it look like there are only a couple of threads in the forum, stifling new activity. There is a way to disable it, but I don't know whether it's a button or check-box or a skin thing. Either that or make the default 6 months or something until traffic has grown significantly.